DAY ONE
Class Discussion:
What is Fuel Efficiency?
The fuel efficiency of a vehicle is defined as the ratio of the energy input into the system to the energy output of the system. People frequently substitute more convenient quantities, such as the number of gallons of gasoline for the input and the number of miles the vehicle travels as the output, or miles per gallon (mpg). Different types of fuel require different substitutions for the input. When determining the overall efficiency of a vehicle, students also might consider values such as cost or greenhouse gas emissions.
Which vehicle is more efficient? Remember the efficiency of vehicles is usually defined as the amount of energy that goes into the vehicle divided by the distance the vehicle moves, which represents the energy that is used by the vehicle.
Let's describe the energy source for the vehicle and how we could easily measure it. In this case, you can define efficiency as the ratio of the distance the vehicle travels.
Student Activity 1:
Let's take a look at the Find a Car site from the Department of Energy website at http://www.fueleconomy.gov/feg/findacar.htm, which compares gas mileage (miles per gallon) averages among different gasoline‐powered vehicles. Let's enter the year, make, and model of a vehicle. It will then give you the estimated miles per gallon and the estimated carbon output of that vehicle along with quite a few other bits of information. Let's identify some models that you can use as comparative examples such as a large SUV versus a compact car. The site notes that these figures can vary quite a bit based on a number of factors. This will be good information where you can begin to consider the things that can affect fuel use in vehicles.
Let us do some comparisons of various makes and models of existing vehicles by accessing the Department of Energy’s Find a Car website at http://www.fueleconomy.gov/feg/findacar.htm, which will allow you to enter the year, make, and model of a vehicle. It will then give you the estimated miles per gallon and the estimated carbon output of that vehicle.
Class Discussion:
Make sure that you read the statement about this being an estimate as in later lessons, I will be talking about how, for the same vehicle, some people can get better gas mileage while some can get worse. This site, though, provides a good way to compare different sizes, makes, models, and years of vehicles. Choose several vehicles that are widely different.
What patterns do you see in the differences and similarities of different sizes, makes, and models?
Student Activity 2:
You should also review the different information pages from the U.S. Department of Energy’s Alternative Fuels and Advanced Vehicle Data Center Web site: http://www.afdc.energy.gov/afdc/ on alternative fuel sources. Note the advantages and disadvantages of each one so that you are prepared to guide students in this area.
Class Discussion:
A type of vehicle power that we will come across in our review is the hybrid electric vehicle. The reason these are so popular now is that they combine two powerful energy sources, electricity and gasoline, to reduce the disadvantages of either one. Engineers realized that energy being lost by gasoline engines could provide the electricity needed as an energy source for an electric motor. The hybrid vehicle grabs energy from the vehicle itself and charges the electric battery, using the “free” electricity to power the car when it can. A computer system switches the gasoline and electric motors on and off as they are needed.
Keep an “Engineering Notebook” so you can record your thinking about each aspect of vehicle design and use. The information in your notebooks will bring your ideas together and can also be used as part of your final project. The notebook is also an excellent way for you to demonstrate your understanding and, thus, serve as a formative assessment tool. I will be reviewing it throughout the module, so I can follow your thinking and analyze your thoughts. I want you to create a notebook or journal using MS Word and save in your team's directory.
Simply Statistics:
2006: 298 million people in the U.S.
2006: 174.9 billion gallons of gasoline burned by highway vehicles
NOTE: Average amount of CO2 released by one gallon of gasoline: approximately 20 lbs.
Think of this last statistic as capturing the emission from burning one gallon of gasoline in a container, then weighing just the CO2 from that collection. Visit the following web page for details: http://www.fueleconomy.gov/feg/contentIncludes/co2_inc.htm – How Can a Gallon of Gasoline Produce 20 Pounds of Carbon Dioxide?.
Student Activity 3:
Working with your team members, look at the figures and do a quick estimate or calculation of the following:
The amount of carbon put into the atmosphere by gasoline each year: 3,498,000,000,000 (3.5 trillion pounds or 1.74 billion tons) ;
The amount of carbon per person in the U.S. each year: about 586 tons;
The amount of gasoline used on average per person in the U.S: 586 gallons.
Class Discussion:
We may not all agree that people use that much gasoline, but these figures includes transportation to get food and other things delivered to them. Imagine what the carbon output is to get bananas to their grocery store from Central America.
Student Activity 4:
Using MS Word, create you Engineering Notebook / Journal and as a team put some of your thoughts about carbon emissions and their effect on the planet’s atmosphere. This notebook will be a way for your team to record the team's thinking, plan out some of the investigations you will do together, and plan out your final project. You may wish to record some of the data you’ve just generated together.
Once they have finished writing out your initial ideas, I want you to continue to think about the reasons why we want to reduce vehicle emissions in the community.
Class Discussion:
Over the next few weeks, you will be learning about ways we can reduce vehicle emissions, but in order for those reductions to have any effect, people in every community have to begin practicing them. You will be continuing to think about the ways in which they can help people in the community to make real changes in their transportation choices and habits.
Student Activity 5:
For the next activities, you will view the two videos from the FuelOurFutureNow.com site: (1) Electric Car versus Gas-powered Sports Car ; (2) Green Gadgets: ZAP! Truck and another video related to the Smart Car on K:\Students\Victor.Rivera\Architectural Draw\Movies\Fuel Efficiency.
Use your engineering journal to take note of the different sources of energy that are being used to power the vehicles in these videos. Also, ask yourself to think about possible ways to define efficiency for the different types of vehicles shown in the videos. In particular, point out that electric vehicles do not have fuel that can be measured in gallons like gasoline.
Divide up into teams. Each team will locate information about a particular kind of alternative fuel for vehicles using the U.S. Department of Energy’s Alternative Fuels and Advanced Vehicle Data Center Web site: http://www.afdc.energy.gov/afdc/. The site is designed as a repository of data for engineers, but the following specific links will save students time. These pages will provide you with a fairly quick summary of what these alternative sources are and why they are of interest.
Biodiesel – http://www.afdc.energy.gov/afdc/fuels/biodiesel_benefits.html and http://www.afdc.energy.gov/afdc/fuels/biodiesel_production.html
Electric – http://www.afdc.energy.gov/afdc/fuels/electricity.html
Ethanol – http://www.afdc.energy.gov/afdc/ethanol/index.html
Hydrogen – http://www.afdc.energy.gov/afdc/fuels/hydrogen.html
Natural Gas – http://www.afdc.energy.gov/afdc/fuels/natural_gas.html
Propane – http://www.afdc.energy.gov/afdc/fuels/propane.html
Use the Alternative Vehicle Energy Sources (PDF) worksheet as an organizer for gathering information about the particular type of alternative energy source for vehicles.
You will be comparing these categories of information across all the alternative fuel types using chart paper to record your team's information under the categories on the worksheet.
Briefly describe in your journal what your team found out about their alternative fuel/energy source.
Note: Remember that all forms of energy will have some advantages and disadvantages. The following are some disadvantages you can discuss if you have not already found this information:
The hydrogen used in fuel cell vehicles comes largely from methane, and CO2 is released into the atmosphere when the hydrogen is produced. Also, large amounts of energy are needed to create hydrogen from methane.
Using electric‐only vehicles requires a “refueling” time of many hours
Growing and processing the corn used for ethanol may release more CO2 than is saved by not burning gasoline. In addition, corn grown for ethanol is then not available as a food resource for people or animals.
Fifty percent of the electricity in the United States is generated by burning coal which has its own CO2 and emission issues.
Let's work in our teams to discuss whether the energy and greenhouse gases used or produced in making a fuel should be considered when thinking about vehicle efficiency. Should these factors be considered when governments set vehicle efficiency standards or offer incentives for buying “green” vehicles?
Record your answers in your team journal, and explain your reasoning.
Student Activity 6:
Go to the Department of Energy website, How Hybrids Work and use the interactive exploration of a gasoline/electric hybrid vehicle’s operation. Review the current problem with electric vehicles, which is their need to be recharged frequently. Remember that our utlimate goal is to use less gasoline.
Answer this question: How does the hybrid electric vehicle help to solve both those problems?
Note: Use the site to discover how, clicking on the various states in which the vehicle uses gasoline, electricity, or both. Note the terms regenerative braking, electric motor drive assist, and automatic start/stop.
Record your team findings in your team Engineering Notebook.
Class Discussion:
Fuel efficiency for gasoline‐powered vehicles is a relatively easy and familiar concept for students, but as the videos show, the future of automobile fuel technology goes beyond choosing from among different kinds of fuels.If computers are available, have students view the Progressive Automotive X PRIZE competition guidelines at http://www.progressiveautoxprize.org/files/downloads/auto/PIAXP_Guidelines_V_1.0_20090110.pdf.
Ten million dollars in prizes will be awarded to the teams that win a competition for clean, affordable, production‐capable, and super fuel‐efficient vehicles that exceed 100 MPG equivalent fuel economy (MPGe). In particular, students should focus on the sections that detail the criteria for an eligible vehicle. If computers are not available, print out pages 29 and 30, which are under the heading “Measuring Fuel Economy, Range, and Emissions.” Students should focus on how the judges will determine fuel efficiency for non‐gasoline‐powered vehicles. Ask students to discuss how this compares to their own efficiency standards.
Evaluate
I want you to describe in your team journals your team's thinking about what factors should be considered in determining vehicle efficiency. What facts should the government provide to help people compare the types of fuel/energy sources?
Remember, I will be receiving a grade on your team journals (e.g., completeness, effort, etc.).
Class Discussion:
Let us review the different ways of defining vehicle efficiency, particularly in reference to different fuel sources.
Today we learned that there are many considerations when attempting to define which vehicle is the most fuel efficient. In Lesson 2, you will learn how driver behaviors can affect the efficiency of vehicles.
Videos & Interactives
Electric Car versus Gas-powered Sports Car The team tests the performance of an electric car against a high-end sports car.
Full Video Green Gadgets: ZAP! Truck Highlights an electric truck that reduces the amount of carbon dioxide released into the atmosphere. The ZAP! Truck is a solar/electric hybrid vehicle that runs on lithium-ion batteries. The truck's solar panels can generate power on a sunny day, or the vehicle can be plugged in to any normal electric socket.
Links
Energy Information Administration
Alternative Fuels and Advanced Vehicles Data Center
Reduce Climate Change - from FuelEconomy.gov
How Can a Gallon of Gasoline Produce 20 Pounds of Carbon Dioxide?
Progressive Automotive X PRIZE competition guidelines (PDF)
Data from U.S. Department of Energy Transportation Energy Data Book (Table 2.11)
Data from U.S. Environmental Protection Agency CO2 calculations
Progressive Automotive X PRIZE Why Progressive?
Downloads